Electric-arc lamp



Patented Feb. 1 5, 1927,

UNITED STATES p Y "1,617,635: PATENT orrlcn.

JOHN.ALLEN HEANY, OF NEW HAVEN, CONNECTICUT, ASSIGNOR TO HEANY LABOR A- TORIES, INC., OF NEW HAVEN, CONNECTICUT, A CORPORATION OF CONNECTICUT.

ELECTRIC-ARC LAMP.

Application filed June 11, 1917, Serial No. 174,100. Renewed December 6, 1926.

The invention relates to electric arc lamps which operate on very low wattages and at 'the ordinary commercial voltages and will 7 maintain high efiiciencies even in the smaller 6 sizes ranging as low as ten or. fifteen candle power. To this end, the invention comprisesa lamp, involving a container or envelope, preferably adapted for connection in the ordinary incandescent lamp socket, and con- 10 taining an inert gas, preferably'under diminished pressure, and two electrodes, between which the arc is maintained, connected to suitable lead wires,'at least one of which electrodes is formed of a mixture of a conductive material and a non-conductive material, such as comminuted tungsten distributed through a body of thorium oxide or zirconium oxide, or a mixture of these refractory oxides, the terminal or are forming portion of such electrode being formed of a second class"conductor,-viz, a body which is non-conducting when cold, but which becomes conductive' when heated to a high deree, the main portion of the electrode ormed of the conductive and non-conductive materials, constituting a ballast resistance for the lamp and'also an incandescing body which utilizes the current absorbed by the resistance to generate light in addition to. that produced at the arc, the electrodes 40 shown a lamp embodying the invention and adapted to be applied to an ordinary incandescent light socket.

Referring to the drawing, 1 indleates the globe or bulb of the lamp which is prefer- Ci ably of the form 'usuallyem 'loyed in incan descent. filament lamps, a apt'ed for the usual socket connection, which is exhausted of air and suppliedlwith an inert gas, such I as nitro en, argon .or the like, preferably under lminished pressure. The bulb is provided with the usual form of glass neck 1"in which is mounted the usual lead wires,

to one of which is connected a conductin and-supporting wire 2, to the lower end o which is secured an electrode-3 having a upon the diameter, the length, and the proportion of refractory metal employed. To

bulbous or spherical head or terminal 4, opposite which electrode is mounted. a second electrode 5, which may be provided with a similar bulbous head or terminal 6, which electrode 5 is preferably mounted on the end of a thermostat 7 anchored in the neck 1' and connected by a suitable conductor 8 to the other lead wire of the lamp. The body portion of one or both of the electrodes 3 and 5 is formed of an intimate admixture of comminuted highly refractory metal, such, for example, as tungsten, and highly refractory oxide, such as oxide of thorium or oxide of zinconium, the metallic constituent being dispersed throughout the body ofthe1elec trode and serving as a conductor of high resistance. This admits of an electrode being. formed of comparatively large diameter and high resistance, the resistance depending the end of said electrode 3 is secured a terminal in the form of a ball or-other suitable shape made of material which constitutes a second class conductor, such tfor example, as a mixture of oxides of zirconium, thorium and yttrium, which is non-conductin when cold, but becomes conductive when highly heated. If desired, the electrode 5, and its terminal 6 may be similar in all respects to electrode 3 and its terminal 4, but, if preferred, the electrode 5 may be made of any suitable conductor of proper form, such as a ball or terminal of metallic tungsten or tun stenv alloy.

Cilmnected to the conductive portions of the electrodes 3 and 5 are two wires 9 and 10 respectively, which are provided with term'inal contacts 11 and 12 of material having anormal low thermionic emissivity such for example as zinc, which are normally in engagement and which together with the conductors 9 and 10 constitute a by-pass or shunt around the terminals 4. and 6 of the electrodes when the lamp is inactive.

The operation of the lamp is as follows:

When current is supplied to the lamp, it

trode is similarly constituted, produces the same effect therein. The heat from said electrodes 3 and 5 raises'the temperature of the terminals 4 and 6 to the necessary degree to convert them intoconductors, ionizes the gas between the terminals, thereby. establishing an arc, and at the same time causes the thermostat 7 to act .to'moveelectrode'5 away from electrode 3 to an efl'ectivearcing distance and a so breaking the circuit through'the by-pass orshunt by separating contacts 11 and 12, which latter moves with electrode 5. It will be understood that if electrode '5 is formed of a highly refractory metal or alloy capable of supporting an arc,

the preliminary heating necessary to start the operation of the lamp will be effected by means of the oppositeelectrode 3, the

operation being inall other respects similar to that just described. Suitable ballast may be included in series with the lamp, in order to take up the voltage of the are when starting, although this is not essential. The effect of the lam as described is the production of a stea y, brilliant are between the electrodes, emitting light of a quality and character closely approximating that of sunlight, the lamp operating under an efliciency of a fraction of a watt per candle power. The light of the arc is augmented by the incandescence of the electrode'or electrodes due to the passage of the current therethrough, andsaid electrodes when con stituted of the materials as described, serve which incandesces at the temperature at which platinum volatilizes and having a terminal formed of a conductor of the second class, a normally closed shunt around said terminal in series with the aforementioned electrode, and means adapted to break the shunt when the terminal is heated sufficiently to become conductive.

- 2, Anarc lamp comprising a container, electrodes therein, at least one of which is formed of a mixture. of highly refractory metallic oxide and highly refractory metal .which incandesces at the temperature at which platinum'volatilizes and having a ter-' minal formedvof a conductor of the second class, a normally closed shunt around said terminal in series with the aforementioned electrode, and a thermostat adapted to. break the shunt when the: terminal is heated sufficiently to become conductive.

3. An arc lamp comprising acontainer,

' electrodes therein', at least one of'which is formed of a mixture of highly refractory metallic oxide and-highly refractory metal shunt.

namesawhich incandesces at the tem erature at which platinum volatilizes an having a 1 terminal formed of a conductor of the second'class, a normally closed shunt around a said terminal in series with the aforementioned electrode, and a thermostat ada ted to move one of said electrodes away rom the other and breakthe shunt when the ter-' minal is heated s'ufiiciently to becomeconductive.

4. An arc lamp COIIlPllSlIlg a container,

platinum volatilizes and having a terminal formed of a conductor of the second class, circuit connections for said electrodes, one of which connections includes 'a thermostat adapted to separate the electrodes to proper arcing distance, and a separable shunt around .the terminal in series with the aforementioned electrode. which is'broken by the ed to separate said electrodes and break the.

6. An arc lam comprising a base, conductors embedde in said base, rod-like electrodes. carried by saidconductors, at least one of which is composed of a-highly refractory' oxide having finely-divided metal uniformly distributed therethrough, a conductive terminal on said electrode, circuit connections for said electrodes including a normally closed shunt around said terminal .in series with said electrode, and a thermostat adapted to separate said electrodes.

.7. An arc lamp, comprisinga container, electrodes therein havin terminal portions formed of conductors of the second class, a normally closed shunt around said'terminal portions, separable contacts in the shunt circuit, and means including a thermostat adapted to separate the contacts-in the shunt when the terminal portions of the electrodes are electrically heated sufiiciently to become conductive.

8. An arc lam comprising a container, separated electro es therein having terminal portions formed of conductors of the second class, a shunt around said terminal portions normally closed when cold, separable contacts in the shunt circuit, and means including a thermostat adapted to separate the contacts in said shunt when current passes between said electrodes.

, In testimony whereof I affix my signature.

' Pwtqit Np: 1,617,635.

Certificate. of Correction.

t Granted February 15, 1927, to

JOHN ALLEN HEANY.-

It is herebyeertified that error a pears in the printed specification of the abovenumbered patent requiring correction as follows: Page -1, line 17, for the word 1 through read tlmoughout, and line 69, for the misspelled word zinconium read zircqniwn; and that the said Letters Patent should be read with these correc ffioe.

Signed and sealed this 28th day of June, A.. D1927. v

- M. J. MOORE,

Acting Oommm'ssz'omr of Patents.

tions therein that the same may conform to the record of the case in the Patent. 

